Thank you ladies! I suspected I wasn't changing often enough after I let him go coverless and realized he peed every 15-30 minutes. I felt like a dope, I totally didn't realize they peed like that. Also, I had the same problem with my daughter, thought that was just how cloth diapering was. It wasn't until I stopped putting her in onesies at about a year old that I realized it was the onesie! Now with my son I have no choice but to put him in onesies because that is what I got in hand me downs. Thankfully I have the covers and flats that never wick!
I think I will still sell most of the pockets though, the flats are much easier to wash.